Mitre boxes are widely employed for cutting workpieces at various angles other than right angular or with precise straight cuts, particularly in cabinet making, in framing of door openings and the like, and making moldings. Various constructions are used and have been proposed for mitre boxes varying from simple channel-shaped structures having guide cuts or slots in their opposed walls to very complex and expensive structures providing a pair of guide posts which receive the saw and one (or both) of which may be moved along the mitre box bed relative to the other to establish the desired angular relationship of the saw relative to guide surfaces against which the workpiece is placed.
Another type of mitre box is one in which a pair of saw guide elements are rotatably supported upon a single post and may be rotated thereabout to establish the desired angular relationship of the saw carried thereby relative to the guide surface and the workpiece. To maintain the saw guide elements in the desired position, they must be locked in the desired rotated position on the post after they have been rotated, and several mechanisms have been proposed therefor. One of the most useful means is a wedge which is movable into and from engagement with detents on a member which is a part of the support structure for the saw guide elements and which is rotatable about the post.
One problem that may occur with such saw guide members is that they limit the downward movement of the saw therebetween so that the depth of the cut in the workpiece is frequently limited by the amount of axial movement permitted the saw guide members upon the post. Moreover, when pad elements are employed on the saw guide members to provide the bearing surfaces, they may not be aligned vertically and thus provide some variation in vertical height of the saw along its length when it abuts them.
It is an object of the present invention to provide a novel mitre box in which the saw is permitted to travel downwardly between the saw guide members to increase the depth of cut permitted.
It is also an object to provide such a mitre box in which the elements may be fabricated readily and relatively economically, and in which slides provide vertically movable biasing surfaces for the saw.
Another object is to provide such a mitre box in which the slides provide bearing pads which are independently movable vertically at the ends of the saw guide member.